Techniques for producing information signal layers in the form of a multilayer structure are widely used to increase the storage capacity of high-density optical recording media such as Blu-ray Disc (BD) (registered trademark)). In a common multilayer optical recording medium, the respective information signal layers have the same reflectance when viewed from the light-receiving surface side. For example, Patent Document 1 discloses that a multilayer optical disk is designed to have three or more recording layers with substantially the same reflectance.
In recent years, there has been a demand for a further increase in the storage capacity of multilayer optical recording media. In order to meet such a demand, studies have been conducted on the use of a method of recording data on both groove and land tracks (hereinafter referred to as the “land/groove recording method” as appropriate) instead of a method of recording data on a groove track (hereinafter referred to as the “groove recording method” as appropriate) for the design of multilayer optical recording media.